← Back to dex
Epic exoplanet 62 EP

KOI-3503 b

RA 293.1508° · Dec 41.7292° · exoplanet

Loading sky survey…
🌌 View in 3D star map
Tonight’s visibility

Computing the sky for your location…

Score breakdown

· 7 badges
62 pts · Epic
Epic 78 pts → Anomaly
  • Denser than iron +18
  • Earth-sized +16
  • Orbits a Sun-like star +8
  • Distant (over 1,000 light-years) +6
  • Multi-planet system +6
  • Confirmed exoplanet +5
  • Found by Kepler +3
Total score 62

16 more points to reach Anomaly.

Badges

  • Confirmed exoplanet · +5
  • Distant (over 1,000 light-years) · +6
  • Earth-sized · +16
  • Denser than iron · +18
  • Multi-planet system · +6
  • Found by Kepler · +3
  • Orbits a Sun-like star · +8

Trivia

What makes it special

  • Earth-sized. Genuinely comparable to Earth in size. Worlds in this narrow band are the ones every next-generation telescope is being pointed at.

Hard to believe

  • Denser than iron. It is packed tighter than solid iron — whatever it is made of, it is not ordinary rock.

What it actually is

  • Hugging its star. It orbits closer to its star than Mercury does to the Sun, completing a lap in less time than Mercury takes.
  • What it is made of. Denser than Earth — a solid world of rock and iron, with no meaningful atmosphere to speak of by mass.
  • Crowded system. One of at least 2 planets orbiting its star.

Sense of scale

  • In perspective. Far away by human standards, yet still a local address inside the Milky Way's spiral arms.

Find it in the sky

  • How to spot it. At magnitude 13.8 it is far too faint for the eye: this one belongs to cameras and long exposures.
  • Northern sky. It rides the northern half of the sky — an easier target the further north you are.

Properties

density gcc
10
diameter km
15179.878
discovery facility
Kepler
discovery method
Transit
discovery year
2021
dist ly
2893.2125
eccentricity
0
eq temp k
785
host star teff
6001
inclination
88.42
insolation
90.2
mag
13.831
mass earth
9.2
name
KOI-3503 b
orbital period days
21.185
radius earth
1.19
semi major au
0.1425
sys num planets
2
sys num stars
1

About KOI-3503 b

KOI-3503 b is an epic exoplanet. It lies about 2,893.2 light-years from Earth, shines at apparent magnitude 13.83, has an equilibrium temperature near 785 K and spans roughly 1.19 Earth radii.

Genuinely comparable to Earth in size. Worlds in this narrow band are the ones every next-generation telescope is being pointed at.

How to see it

At apparent magnitude 13.83, it takes a larger telescope or a long-exposure image to capture.

Like any astronomical target, KOI-3503 b is best seen from a dark site away from city lights, and when it is above the horizon depends on your latitude and the time of year. The visibility panel above works out tonight's viewing window for your saved location.

Why KOI-3503 b is an epic exoplanet

KOI-3503 b scores 62 points on Spacedle's rarity scale, which places it in the epic tier. Another 16 points would lift it into a rarer tier.

That score comes from 7 science badges — Confirmed exoplanet, Distant (over 1,000 light-years), Earth-sized, Denser than iron, Multi-planet system, Found by Kepler and Orbits a Sun-like star — each earned for a real, measurable property of the object. Rarity on Spacedle is never random: the more remarkable an object's astrophysics, the more badges it collects, the higher it scores, and the rarer it ranks.